Stereophone ear plug insert



FIG. 1 is a front perspective view of a stereophone ear plug insert showing our new design;

FIG. 2 is a side elevational view thereof, with the opposite side being a mirror image;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a front view thereof.

The broken lines shown in all figures are for illustrative environmental purposes only and form no part of the claimed design. 

The ornamental design for a stereophone ear plug insert, as shown and described. 